Your gateway to a wide range of natural resources information and associated maps

Victorian Resources Online

Hardpans in the Wodonga-Tallangatta Region

In north-eastern Victoria, both duripans and fragipans are found. Many of the soils of the valley piedmont between Wodonga and Tallangatta have a hardpan at the base or within the solum. The soils above the hardpans typically have fine particle-size modes which indicate the presence of significant aeolian accessions (Rowe 1994). The stratigraphic relationships between the soils and the hardpans suggest that the latter mark the change from a period of widespread surface erosion to a period of sediment accession on less-steep slopes. It was therefore proposed that these hardpan layers initiatially occurred during a period when aridity had caused a decline in vegetative ground-cover and increased surface run-off and widespread erosion and sedimentation.

Peaks of aridity in south-eastern Australia have been ascribed to glacial periods (Galloway 1965; Bowler et al. 1976; Williams 1984) and it is proposed that the initiation of the hardpans occurred during these periods when desiccation of surface materials would have been severe. Some of these materials would have undergone consolidation as a result of high suction pressures resulting from removal of water from the finer soil pores (Aitcheson 1956, 1971; Smeck et al. 1989; Chartres et al. 1990). The degree of consolidation possible would depend on the presence of sufficient fines to create high suction pressures. Coarse surface materials would need to be infiltrated by clays to achieve these conditions (Brewer et al. 1972) and aeolian accessions during arid periods would meet this requirement. Well weathered saprolite of granitic or other similar coarse grained rocks, exposed by surface erosion at these times would also have been susceptible.

Image:  Location of the hardpan sites within the Wodonga-Tallangatta region.
Location of the hardpan sites within the Wodonga-Tallangatta region.



    This map shows sites studied by Ken Rowe as part of his PhD thesis on the development of
    pedogenic hardpans in North east Victoria.

    Information relevant to many of these sites is presented on this website.

Table 1: Sites in the North East region where pedogenic hardpans have been described.
Further details can be found for these sites by clicking on the link.

Site No.
General LocationSite LocationSite Description
1
Glenrowan Railway CuttingWangarattaMultiple hardpans in granitic alluvium/colluvium, over mottled (lateritised sediments and saprolite in Glenrowan Gap.
2
Tallangatta Railway CuttingTallangatta
515300E, 5991300
Single hardpan (duripan) in complex alluvial fan of gneissic sediments, over mottled sediments and saprolite.
3
Riversdale West CuttingTallangatta
517600E, 5991900N
Single hardpan (duripan in piedmont slope-mantle sediments and gneissic saprolite.
4
Tallangatta ForeshoreTallangatta
515300E, 5992400N
Cemented Pliocene river gravels with polygonal crack patterns and cemented crack-infill sediments.
5
Packer's Railway CuttingTallangatta
512400E, 5991300N
Single hardpan (duripan) in schistose lower-slope sediments: polygonal crack pattern and cemented infill.
6
Bonegilla Railway SidingAlbury
499100E, 6000300N
Cemented Pliocene river gravels, overlain by thick, well-weathered fine sediments- probably aeolian.
7
Murray Valley Highway at BonegillaAlbury
499100E, 6000400N
Cemented Pliocene river gravels below a shallow red duplex soil.
8
Murray Valley Highway Railway Bridge at BonegillaTallangatta
500800E, 5999900N
Cemented Pliocene river gravels with polygonal crack patterns and cemented fine infill.
9
Hillsbrae Cemented GravelsTallangatta
509400E, 5991400N
Cemented Pliocene river gravels exposed by water erosion by Lake Hume at full supply level.
10
Sandy Inlet-Lake HumeTallangatta
508000E, 5989000N
Cemented slope sediments with polygonal crack infill pattern exposed by water erosion by Lake Hume at full supply level.
11
Murray Valley Highway at Sandy InletTallangatta
508300E, 5988200N
Hardpan exposed in road cutting in gneissic/schistose sediments on lower piedmont slope below shallow duplex soil.
12
Yabba Road CuttingTallangatta
526200E, 5977100N
Hardpan (duripan) in road cutting in granitic sediments on valley piedmont.
13
Bryant's Gap Road CuttingTallangatta
512400E, 5989400N
Hardpan (duripan) in road cutting in granitic sediments on valley piedmont.
14
Garvey's Hill: Sluiced PitTallangatta
486100E, 5978100N
Thick (1m) duripan over hightly weathered river gravels, exposed in an area sluiced for gold; on a hill top.
15
Riversdale East Rail CuttingTallangatta
518200E, 5991900N
Hardpan (fragipan) in gneissic sediments on a gentle slope on a remnant of valley piedmont.


The most common form of hardpan in this area is a duripan which occurs as a single layer in alluvial-colluvial slope deposits on the long gentle piedmont slopes. It has been referred to as the Tallangatta Hardpan (Rowe 1994) because of its consistent form and stratigraphic relationships in the Tallangatta area. The Tallangatta Hardpan is well represented in road and railway cuttings both east and west of Tallangatta and its relationship to the valley piedmont is illustrated in Figure 2a, Figure 2b, Figure 2c, Figure 2d, and Figure 2f. It commonly occurs 1-2 m below the present soil surface and in most cases lies more-or-less parallel to the surface Figure 3 and Figure 4; Photo 2 , Photo 3, Photo 6, Photo 7, Photo 9 and Photo 10. It has a relatively clear, planar upper surface but the lower boundary is commonly less clear and irregular. Although the hardpan is usually massive, it may have a laminated structure. The thickness is variable but is commonly about 0.5 m. Although the Tallangatta Hardpans have generally formed in alluvial-colluvial sediments, where weathered bedrock occurs at the same general level as the hardpan in the sediments Figure 4, it takes the form of an indurated layer in the upper zone of the saprolite.

The Tallangatta Hardpan typically has vertical cracks up to a centimetre wide extending through its depth. In horizontal exposures these form a polygonal crack pattern with a diameter of up to half a metre. The vertical cracks are filled with hard, brittle, grey-brown indurated material which appears to be silicified fine sediments. The crack-fill material may stand clear of the surface where weathering has softened and eroded the hardpan surface.
Page top